Q: What is the brake-shift interlock?

All cars today have an interlock system that’s designed to prevent the car from being put into gear if your foot isn’t on the brake. This does two things. First and foremost, it ensures that you can’t accidentally knock the car from Park into gear. Second, it ensures that your brake lights are working (the brake light switch is part of the interlock system and if it fails, the transmission won’t shift, preventing you from driving without brake lights).

If you can’t shift out of Park, check the fuses first and then the brake light switch. If an inspection shows neither is the problem, you’ll need to access the brake-shift interlock switch, which is located under the trim at your gearshift. Because of the amount of teardown and the potential to damage trim pieces, it’s recommended that you have your car professionally serviced.